1. Field of the Invention
The present invention relates to an electrical connector box, and particularly to an automotive electrical connector box including a threaded bolt that attaches an electrical wire terminal to a bus bar, a nut molded into a nut bracket positioned beneath the bus bar, and a nut holding portion of the nut bracket reinforced to prevent damage to the nut bracket when the bolt is tightened.
2. Description of the Related Art
Japanese Kokai Patent 2001-52772 discloses a terminal attachment structure as illustrated in FIG. 6. Electrical connector box 1 includes attachment fixture 2a that projects from the outer wall of case 2, and threaded bolt 3 is molded into the inner portion of attachment fixture 2a. Bolt hole 4a, which is formed within LA terminal 4 on the end of power lead ‘w’, is placed over bolt 3, and nut 5 is tightened on bolt 3 to make the electrical connection. Attachment fixture 2a contains a bus bar (not illustrated in the drawing) that connects to bolt 3, extends into the internal portion of case 2, and joins to an electrical circuit contained therein.
Furthermore, as illustrated by the connector box structure 1′ in FIGS. 7 and 8, in order to connect the bus bar to the power supply wire, nut bracket 2b′ is formed as an integral part of electrical connector box 1′ with one end of bus bar 6 extending over the upper surface of nut bracket 2b′ into which nut 5 is molded. The end of bus bar 6 is placed over the upper surface of nut 5; the bolt hole in bus bar 6 is aligned over nut 5; LA terminal 4, to which the terminal end of power lead ‘w’ is attached, is placed against the upper surface of bus bar 6; and bolt 7 is inserted into the bolt holes provided in the LA terminal and bus bar, and tightened into nut 5. Nut 5 is buried within the center portion of the top wall of nut bracket 2b′ which is formed with an open passage that aligns with the nut, and indented outer wall 2d′ extends downward from the end of the top wall.
The connector box shown in FIG. 6 exhibits an undesirable feature in that attachment fixture 2a projects outward from the connector box case and thus increases the size of the connector box. Also, there is a risk that attachment part 2a may be damaged when nut 5 is tightened on bolt 3 even though fixture 2a is required to support the torque needed to attach nut 5.
Moreover, as illustrated by the connector box structure shown in FIGS. 7 and 8, in order to locate the power supply wire and bus bar connection within the connector box case to eliminate the problem of the attachment part adding to the size of the case, thin wall section X, which is the portion of nut bracket 2b′ at outer wall 2d′, must be narrowed to provide for an adequate wire insertion space ‘S’ between bus bar 6 and the outer wall. Thus, it is likely that thin wall section X will be damaged by the torque applied to tighten the bolt into nut 5, thereby posing the same type of connection support problem as noted for the structure illustrated in FIG. 6.